A70-32 An Unexpected Culprit: Peritoneal Tuberculosis Uncovered After Pulmonary Embolism

Abstract Introduction Tuberculosis (TB) is a chronic infectious disease caused by Mycobacterium tuberculosis, most commonly involving the lungs but capable of affecting nearly any organ system. Extrapulmonary TB accounts for 15-20% of all cases and can pose a significant diagnostic challenge. We present an atypical case of peritoneal tuberculosis in an immunocompetent male who presented with pulmonary embolism and no abdominal symptoms. Case A 39-year-old man from India with prior typhoid and dengue presented with one month of intermittent fevers, dyspnea, and fatigue. Prior to presentation, he had completed two outpatient courses of levofloxacin for presumed pneumonia without improvement. Computed Tomography (CT) Angiography of the chest showed dense contrast in the superior vena cava with surrounding artifact and a small filling defect in the left interlobar artery; heparin infusion was initiated for suspected pulmonary embolism. It also partially visualized abnormal omental and mesenteric inflammation in the upper abdomen. This finding, along with the unprovoked nature of the pulmonary embolism, prompted a CT scan of the abdomen and pelvis to evaluate for occult malignancy and other pathologies. CT Abdomen/Pelvis revealed extensive omental and mesenteric infiltration and right sided perihepatic and right paracolic gutter ascites with partial loculation. QuantiFERON-TB Gold was positive, and three sputum AFB cultures were negative. CT-guided omental biopsy was pursued on hospital day 5, demonstrating necrotizing granulomatous inflammation, positive for acid-fast bacilli and M. tuberculosis complex. The patient was officially diagnosed with peritoneal tuberculosis. He completed nine months of RIPE therapy with marked clinical improvement and near-resolution of findings on follow-up imaging. Discussion Tuberculosis is a recognized hypercoagulable state, with meta-analyses showing increased venous-thromboembolism risk driven by systemic inflammation. Most reports link this to pulmonary TB; VTE associated with extrapulmonary TB is rarely described. Peritoneal TB, a subset of gastrointestinal TB that most often affects the ileocecal region, peritoneum, or omentum, is uncommon even in endemic regions. Rarely, Mycobacterium bovis—typically resistant to pyrazinamide—can cause peritoneal or gastrointestinal TB through ingestion of unpasteurized milk, a notable public-health consideration as nationwide PZA-resistance testing remains limited. Case reports of peritoneal TB with thrombosis usually describe portal or mesenteric vein involvement rather than pulmonary embolism, making this presentation exceptionally rare. Conclusion Peritoneal TB may present atypically with thromboembolic complications despite absent abdominal symptoms. Clinicians should consider extrapulmonary TB in patients from endemic regions with unexplained VTE and remain aware of M. bovis as a foodborne, PZA-resistant cause of gastrointestinal TB. This abstract is funded by: None